New research finds that consumers have a higher potential of benzene exposure
in the environment than by using sunscreen
TAMPA FL, December 5, 2022 — In early 2021, testing of several consumer products — including sunscreen and deodorants — revealed trace amounts of benzene, a known human carcinogen. Since then, the U.S. Food and Drug Administration (FDA) has confirmed benzene contamination in many products, announced numerous recalls, and in December 2021 formally requested manufacturers to test for benzene. A flurry of news stories have focused on the dangers of using sunscreen.
But a new toxicological study has found that the concentration of benzene found in sunscreen poses a lower potential for health effects in humans than exposure to benzene in the environment, the workplace, and in contaminated foods like bananas. Toxicologists Robinan Gentry and Debra Kaden, of Ramboll US Consulting, Inc., urge consumers to weigh the benefits of using sunscreen with that of exposing their skin to cancer-causing UV rays. Gentry will present their findings during the Society for Risk Analysis Annual Meeting, Dec. 4-8 in Tampa, Florida.
Her presentation is part of a symposium titled “Benzene Contamination in Consumer Products: Exposures and Implications for Human Health and the Environment.” The other three presenters in the session are:
In studies of both humans and lab animals, benzene has been associated with leukemia and other blood-related cancers. It is classified as a human carcinogen by the U.S. Environmental Protection Agency (EPA). Benzene can be inhaled, ingested, or absorbed through the skin. A natural component of crude oil, it is used to produce plastics, rubber, drugs, detergents, and pesticides. People are exposed to benzene in the environment when they breathe in car emissions, gasoline vapor, forest-fire smoke, and tobacco smoke. (The American Cancer Society has reported that cigarette smoke accounts for about half of our exposure to benzene.)
While Gentry and Kaden acknowledge that benzene can be hazardous in certain situations, they wanted to take “a realistic approach” to comparing potential health impacts that exposures from benzene as a trace contaminant in sunscreen (sprays and lotions) may have on blood concentrations of benzene. Their research followed the results of the 2021 report from the independent lab Valisure, which found that 78 sunscreen and after-sun care products out of nearly 300 batches from 69 different companies were contaminated with 0.1 to 6.26 parts per million (ppm) of benzene.
“In the case of benzene, the health effects of concern (blood disorders) result from delivery of benzene to the bone marrow,” says Gentry. “So we wanted to look at potential concentrations in the blood that could result from the use of sunscreen.” The team’s analysis combined what is known about the pharmacokinetics of benzene (how it is absorbed by and passes through the body) with exposure modeling of use of the products identified by Valisure. They took a conservative screening approach in estimating exposures, assuming that all of the benzene that was applied to the skin crossed the skin barrier. For their inhalation model, they evaluated exposure levels if an individual applied the sunscreen in a small closed bathroom, rather than outdoors.
Based on the concentrations of benzene reported in the products, they modeled both dermal and inhalation exposures. They adjusted for inhalation rate, how much could be absorbed, and the time required for that to happen. All of this allowed them to estimate how much benzene could get into the blood.
Their results indicate that the concentration of benzene that could enter the blood following the use of spray or lotion sunscreen is far less than other known exposures to benzene, including:
Gentry and Kaden found that the duration of exposure to benzene is critical with regards to understanding the potential for health effects. “The determination of the potential for health effects following exposure to benzene was based on results of studies in workers with long-term (up to 40 years) exposure at concentrations of 10 ppm or greater,” says Gentry. “Our estimates of the intake or absorption of sunscreen indicated far less than ppm concentrations measured in the sunscreens.” As Kaden points out, “The intake of benzene from sunscreens was actually lower than intake that would result from eating a banana, according to concentrations of benzene reported in one study.”
By conducting their analysis, the researchers wanted to make it clear that the presence and concentration of a chemical in a product alone does not indicate its potential for health effects. Rather, it’s important to understand the potential exposures and intake from use of a product and how that compares to exposure levels and durations of exposures that have been associated with health effects (in this case, blood disorders).
“There is more to understanding risk than just understanding exposure to a hazardous substance,” says Kaden.
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